<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .box {
        width: 200px;
        height: 200px;
        border: 3px solid #000;
        font-size: 30px;
        margin-top: 10px;
      }
      .pink {
        background-color: pink;
      }
      .big {
        width: 300px;
        height: 300px;
      }
    </style>
  </head>
  <body>
    <div id="app">
      <div class="box" :class="obj">黑马程序员</div>
      <div class="box" :class="classNames">黑马程序员</div>
    </div>
    <script src="./vue.js"></script>
    <script>
      const app = new Vue({
        el: '#app',
        data: {
          flag: false,
          obj: { pink: true, big: false },
          classNames: ['pink', 'big'],
        },
      });
    </script>
  </body>
</html>
